ratch·et /ˈræʧət/
制輪裝置;[防倒轉的] 棘齒
ratchet
棘輪
Ratch·et n.
1. A pawl, click, or detent, for holding or propelling a ratchet wheel, or ratch, etc.
2. A mechanism composed of a ratchet wheel, or ratch, and pawl. See Ratchet wheel, below, and 2d Ratch.
Ratchet brace Mech., a boring brace, having a ratchet wheel and pawl for rotating the tool by back and forth movements of the brace handle.
Ratchet drill, a portable machine for working a drill by hand, consisting of a hand lever carrying at one end a drill holder which is revolved by means of a ratchet wheel and pawl, by swinging the lever back and forth.
Ratchet wheel Mach., a circular wheel having teeth, usually angular, with which a reciprocating pawl engages to turn the wheel forward, or a stationary pawl to hold it from turning backward.
Note: ☞ In the cut, the moving pawl c slides over the teeth in one direction, but in returning, draws the wheel with it, while the pawl d prevents it from turning in the contrary direction.
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ratchet
n : mechanical device consisting of a toothed wheel or rack
engaged with a pawl that permits it to move in only one
direction [syn: rachet, ratch]
v : move by degrees in one direction only; "a ratcheting lopping
tool" [syn: rachet up, ratchet down]